After the kansas-nebraska act passed, northerners headed for kansas because
a. the climate and rich soil promised better farming than the north could offer.
b. they wanted to create an antislavery majority there.
c. jobs working on the transcontinental railroad were available there.
d. southern immigrants there were campaigning to secede from the union.

zheng he was a chinese explorer who lead seven great voyages on behalf of the chinese emperor. his seven total voyages were diplomatic, military, and trading ventures, and lasted from 1405 – 1433. however, most historians agree their main purpose was to promote the glory of ming dynasty china.

explanation:

demand is the need and oportunity to buy a given good or service.